There have been 70 people who have served as governor, over 73 distinct terms. Additionally, Henry Molleston was elected, but died before he could take office. Only four governors have been elected to two consecutive terms, with the longest-serving being Ruth Ann Minner, who was elected twice after succeeding to the office, serving a total of just over eight years. The shortest term is that of Dale E. Wolf, who served 18 days following his predecessor's resignation; David P. Buckson served 19 days under similar circumstances. The current governor is Jack Markell, who took office on January 20, 2009; his second term expires on January 17, 2017.

In 1776, soon after Delaware and the other Thirteen Colonies declared independence from Britain, the state adopted its first state constitution. It created the office of President of Delaware, a chief executive to be chosen by the legislature to serve a term of three years.[4]

The office of President was renamed Governor by the constitution of 1792,[5] which set the commencement date of the term to the third Tuesday in the January following an election, and limited governors to serving only three out of any six years.[6] The term was lengthened to four years by the 1831 constitution, but governors were limited to a single term.[7] The current constitution of 1897 allows governors to serve two terms.[8]

The 1776 constitution stated that if the presidency were vacant, the speaker of the legislative council would be a vice-president.[9] The 1792 constitution has the speaker of the senate exercising the office when it is vacant, and the 1897 constitution created the office of lieutenant governor,[10] upon whom the office devolves in case of vacancy.[11] The offices of governor and lieutenant governor are elected at the same time but not on the same ticket.

Seventeen of Delaware's governors have held other high offices, with six representing Delaware in the Continental Congress and twelve representing the state in the U.S. Congress. Two have served as President of Pennsylvania. Four (marked with *) resigned to take other offices, three in the U.S. Congress and one to be President of Pennsylvania.

All representatives and senators listed represented Delaware except where noted.

As of May 2015[update], there are six former U.S. governors who are currently living at this time, the oldest U.S. governor of Delaware being David P. Buckson (1960–1961, born 1920). The most recent death of a former U.S. governor of Delaware was that of Russell W. Peterson (1969–1973), who died on February 20, 2011. The most recently serving U.S. governor of Delaware to die was Sherman W. Tribbitt (1973–1977), who died on August 14, 2010.

^The office of lieutenant governor was created in the 1897 constitution, with the first election taking place in 1900.

^Lieutenant governors were members of the same party as the governor except where noted.

^The fractional terms of some governors are not to be understood absolutely literally; rather, they are meant to show single terms during which multiple governors served, because of resignations, deaths and the like.

^McKinly was captured and taken prisoner by British forces.[12] He was exchanged for loyalist Governor William Franklin of New Jersey in August 1778.[13] Most sources do not specify the day McKinly was captured; at least one specifies that McKinly and the city of Wilmington were captured the day after the Battle of Brandywine, which was on September 11, 1777.[14]

^As Speaker of the Assembly, acted as chief executive following the capture of President McKinly until the return of Speaker of the Legislative Council George Read, who was the righful successor, from the Continental Congress in Philadelphia.[15]

^ abAs Speaker of the Legislative Council, served as vice-president for unexpired term.

^Resigned; was elected President of Pennsylvania and took office November 7, 1782, holding both presidencies simultaneously until his resignation.

^As Speaker of the Legislative Council, served as vice-president until a special election was held.

^ abGovernor-elect Henry Molleston died on November 11, 1819, before taking office. The newly elected state senate chose a speaker, Jacob Stout, who would act as governor for one year of Molleston's term before a special election was held to pick a governor for the remaining two years.[16]

^ abThere is disagreement over when Haslet died and Thomas became acting governor. Most modern sources say Haslet died on June 20, and Thomas became acting governor on June 23; however, some sources say Thomas became acting governor on June 20,[17] and others say Haslet died on June 23,[18] both situations meaning there was no gap in power.

^Because of the death of Governor Haslet so early in his term, elections were called early. Unlike when elections were called due to Henry Molleston's death, where the election was only for the final two years of his term, in this case the new election was for a new three-year term, causing the election schedule to shift.[16]

^Bennett was the first governor elected under the terms of the 1831 constitution, which lengthened terms to four years.

^As Speaker of the Senate, acted as governor for unexpired term, and was subsequently elected in their own right.

^Because of the death of Governor Marvil so early in his term, the General Assembly decided to conduct an election in 1896, to coincide with the election for President of the United States; thus, Watson was limited to filling out a two-year term.[19]

^"Read, George". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Rodney, Caesar". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Dickinson, John". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Van Dyke, Nicholas". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Clayton, Joshua". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Bassett, Richard". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Mitchell, Nathaniel". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Rodney, Daniel". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Temple, William". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Biggs, Benjamin Thomas". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Townsend, John Gillis, Jr.". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Buck, Clayton Douglass". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Boggs, James Caleb". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"du Pont, Pierre Samuel, IV". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Castle, Michael Newbold". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.

^"Carper, Thomas Richard". Biographical Directory of the United States Congress. Clerk of the United States House of Representatives and Historian of the United States Senate. Retrieved June 12, 2009.